If the housing has that much oxidation, you won't have good conductivity anyway, as oxide is an insulator. I would consider Paul's idea of adding a thin layer of solder to the outside of the socket if you need a tight fit after cleaning. If you're careful, you should be able to avoid damaging the wiring. If it does melt the insulation or something else is ruined, you can use the wiring and springs out of new sockets and splice them in. Use an interweave butt joint when you solder the wires and cover with waterproof heat shrink tubing and you won't have any problems. I'd also use some di-electric grease to keep the contact area from oxidating again.
Steve